Recent content by logic smogic
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Identical Particles in a 1-D Harmonic Oscillator
So (a) is one since they will all be in the same state. But (c) will be E_{0} has degeneracy 2, since they will each be in the ground state, but each can either be up or down (or since the Hamiltonian is just a superposition of the different individual particles Hamiltonians, is it (3!=6)?)...- logic smogic
- Post #5
- Forum: Advanced Physics Homework Help
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Perturbed Ground State Wavefunction with Parity
Any thoughts on this? The basic question here is: How does parity create selection rules? Perhaps someone could just lay out it for me, or point me to a nice tutorial. My book doesn't provide an example or anything of that sort, and I have an exam today! Thanks much.- logic smogic
- Post #2
- Forum: Advanced Physics Homework Help
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Identical Particles in a 1-D Harmonic Oscillator
a.) Oh, I think I see. I was thinking of degeneracy wrong? It refers to the number of possible states with a particular energy, not the number of particles occupying a specific energy level, right? How would I go about determining the degeneracy of a system like this? (of course, I'll do the...- logic smogic
- Post #3
- Forum: Advanced Physics Homework Help
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Identical Particles in a 1-D Harmonic Oscillator
[SOLVED] Identical Particles in a 1-D Harmonic Oscillator Homework Statement Three particles are confined in a 1-D harmonic oscillator potential. Determine the energy and the degeneracy of the ground state for the following three cases. (a) The particles are identical bosons (say, spin 0)...- logic smogic
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- Harmonic Harmonic oscillator Identical particles Oscillator Particles
- Replies: 6
- Forum: Advanced Physics Homework Help
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Perturbed Ground State Wavefunction with Parity
[SOLVED] Perturbed Ground State Wavefunction with Parity Homework Statement A particle is in a Coulomb potential H_{0}=\frac{|p|^{2}}{2m} - \frac{e^{2}}{|r|} When a perturbation V (which does not involve spin) is added, the ground state of H_{0} + V may be written |\Psi_{0}\rangle =...- logic smogic
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- Ground Ground state Parity State Wavefunction
- Replies: 3
- Forum: Advanced Physics Homework Help
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Potential Energy of a Two Spring, Two Mass System
Because we're evalutating the system in equilibrium, right? Well, I'm saying that the total potential energy contribution from the springs is, V_{springs} = \frac{1}{2} k (y_{1} - y_{01})^{2} + \frac{1}{2} k [(y_{2}-y_{02})-(y_{1}-y_{01})]^{2} ...where you can see I've accommodated...- logic smogic
- Post #3
- Forum: Advanced Physics Homework Help
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Potential Energy of a Two Spring, Two Mass System
Homework Statement Find the total potential energy described by a system consisting of a mass hanging by a spring, connected to a second mass also hanging by a spring. Assume that the masses are the same, and the springs are identical (in spring constant and length). Homework Equations...- logic smogic
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- Energy Mass Potential Potential energy Spring System
- Replies: 3
- Forum: Advanced Physics Homework Help
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Tricky Integral, H-Atom Dipole Transition Matrix Elements
Ah, I must've had my convention backwards. That fixes everything - thanks!- logic smogic
- Post #6
- Forum: Advanced Physics Homework Help
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Tricky Integral, H-Atom Dipole Transition Matrix Elements
Great, I got it. Thanks. Quick question, though. What is: \int_{0}^{2 \pi} \sin \phi d \phi Isn't it zero? But then all of my matrix elements would go to zero when evaluated in spherical coordinates (where \phi is evaluate from 0 \rightarrow 2 \pi). It seems like cheating to evaluate it...- logic smogic
- Post #4
- Forum: Advanced Physics Homework Help
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Tricky Integral, H-Atom Dipole Transition Matrix Elements
I started in spherical, and had a tough time with it. But maybe I was turning to the definite integral tables too early. Looks like if I do integration by parts two (or maybe three?) times, it should take a familiar form. Alright, I'll give it a shot.- logic smogic
- Post #3
- Forum: Advanced Physics Homework Help
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Tricky Integral, H-Atom Dipole Transition Matrix Elements
1. Problem Evaluate \int_{-\infty}^{\infty} \int_{-\infty}^{\infty} \int_{-\infty}^{\infty} z^{2} e^{-A \sqrt{x^{2}+y^{2}+z^{2}}} dxdydz 2. Useful Formulae none 3. Attempt at Solution Well, this is part of a much larger problem. I am trying to compute the dipole moment matrix elements...- logic smogic
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- Dipole Elements Integral Matrix Transition Transition matrix
- Replies: 6
- Forum: Advanced Physics Homework Help
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Springs, Normal Modes, and Center of Mass coordinates
Alright, it took 5 more pages of algebra, but I got it.- logic smogic
- Post #5
- Forum: Advanced Physics Homework Help
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Springs, Normal Modes, and Center of Mass coordinates
Progress Report Alright, I was clearly looking at this incorrectly. (Perhaps that's why I've had 120+ views, and zero replies in almost 2 weeks.) Again, the given equations: Energies for Triatomic Model in Cartesian Coordinates: V=\frac{k}{2}(x_{2}-x_{1}-b)^{2}+\frac{k}{2}(x_{3}-x_{2}-b)^{2}...- logic smogic
- Post #4
- Forum: Advanced Physics Homework Help
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Springs, Normal Modes, and Center of Mass coordinates
Hi all - it's been a week, and I still haven't made any progress on this problem. There must be some simple algebra trick I'm missing here. Or maybe my method is completely off? Any thoughts at all?- logic smogic
- Post #3
- Forum: Advanced Physics Homework Help
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Springs, Normal Modes, and Center of Mass coordinates
Let me just add specifically some steps I've taken: R = \frac{\sum m_{i} x_{i}}{\sum m_{i}} = \frac{m(x_{1} + x_{3}) + M x_{2}}{2m + M} = 0 \rightarrow m(x_{1} + x_{3}) + M x_{2} = 0 \rightarrow x_{2} = - \frac{m}{M} (x_{1} + x_{3}) Now using, y_{1} = x_{2} - x_{1} y_{2} = x_{3} - x_{2} I...- logic smogic
- Post #2
- Forum: Advanced Physics Homework Help